/Engine/Source/Runtime/Engine/Public/SkeletalMeshDeformerHelpers.h
Allocate and bind a new tangent buffer and return it for writing. Ownership is handled by the MeshObject. If we call this more than once for the same MeshObject in the same frame then we return the allocation from the first call.
static [FRDGBuffer](API\Runtime\RenderCore\FRDGBuffer) * AllocateVertexFactoryTangentBuffer ( [FRDGBuilder](API\Runtime\RenderCore\FRDGBuilder) & GraphBuilder, [FSkeletalMeshObject](API\Runtime\Engine\FSkeletalMeshObject) * InMeshObject, int32 InLodIndex, TCHAR const * InBufferName )